you dont HAVE to lower the compression... apparently its all in the tune, there are a few high compression turbos about... including dales old ep91 (austarletclub.com) that had a tdo4l turbo strapped straight on a n/a 4efe and was pushing 220bhp. which untill he sold it was running fine. but were getting a bit off the point here... stixnolan, if your engine has the jdm inlet manifold on it listed above you already have one of the most powerful versions of the 4efe, and there isnt much in the way of after market performance parts available for the 4efe but if your wanting to stay n/a, a panel filter helps to iron out a few flat spots across the range, and a downpipe back exhaust system will probably help bring the revs up a bit quicker, and if your going down that route i would consider a 4 branch exhaust manifold, you can get these for the 5efe paseo off ebay.com that will fit. also maybe consider a set of 5efhe cams which have slightly higher lift and slightly longer duration... you can get these off andrew cliffe (toyotasera.co.uk). other than that you could get the head skimmed (to increase the compression) ported and polished or maybe fit a 1.5 5efe 98bhp which drops in with no issues... but your close to that sort of power anyway. hope that helps. Rich.